Manufacture of trialkylaluminum compounds and α-alcohols

ABSTRACT

Higher trialkylaluminum compounds may be made by forming α-olefin by oligomerizing ethylene using a transition metal containing catalyst, reacting the α-olefins formed with a lower trialkylaluminum compound to form higher trialkylaluminum compound(s) These may optionally be oxidized, as with oxygen, to form higher trialkoxyaluminum compound, which in turn may be hydrolyzed to α-alcohols. In one variation of the process lower α-olefins and higher (relatively) α-alcohols may be formed and isolated. Higher trialkylaluminum compounds and α-alcohols are useful as chemical intermediates, while lower α-olefins are useful as monomers for polyolefins.

This application claims the benefit of Provisional Application No.60/340,443, filed Dec. 12, 2001.

FIELD OF THE INVENTION

α-Olefins are manufactured by oligomerizing ethylene using a transitionmetal containing catalyst, the α-olefins are converted to highertrialkylaluminum compounds by contacting the α-olefins with a lowertrialkylaluminum compound usually with heating. The highertrialkylaluminum compounds which are formed may be reacted with oxygento form the corresponding trialkoxyaluminum compounds, which can behydrolyzed to form α-alcohols.

TECHNICAL BACKGROUND

Higher trialkylaluminum compounds (HTAC), R³⁰ ₃Al (I), in which thealkyl groups contain more than 4 carbon atoms, are useful particularlyas chemical intermediates for the synthesis of α-alcohols of the formulaR³²R³³CHCH₂OH (II) wherein R³² is hydrogen or alkyl and R³³ is alkyl.α-Alcohols containing 10 to 20 carbon atoms are useful as intermediatesfor the synthesis of detergents and other surfactants. Thereforeimproved methods of making (I) and/or (II) are commercial interest.

Generally speaking, linear α-alcohols are often made utilizing thefollowing steps, see for instance B. Elvers, et al., Ed., Ullmann'sEncyclopedia of Industrial Chemistry, 5^(th) Ed., Vol. A28, 1996, p.505-508 and references therein, and J. I. Kroschwitz, et al., Ed,Encyclopedia of Chemical Technology, 4^(th) Ed., Vol. 1, John Wiley &Sons, New York, p. 894-903 and references therein, both of which arehereby included by reference.

-   -   (a) Triethylaluminum is produced by contacting under relatively        high pressure and temperature a mixture of aluminum, hydrogen,        ethylene and triethylaluminum (TEA). “New” TEA is produced in        the reactor. The liquid product is removed from the reactor,        filtered and some is recycled back to the TEA reactor and some        is used in the next step.    -   (b) The TEA used in the next step is now mixed with more        ethylene under high pressure and with heating. The ethylene adds        sequentially (oligomerizes) to each of the original ethyl groups        in the TEA, forming HTACs.    -   (c) The product of the previous step is mixed with oxygen (a        highly exothermic reaction) to form the corresponding        trialkoxyaluminum compounds.    -   (d) The trialkoxyaluminum compounds are hydrolyzed to form an        alpha-alcohol mixture and alumina.

This process is effective but requires the use of high temperatures andpressures in two steps, and in these two steps pyrophoric alkylaluminumcompounds are present, and so these steps must be done very carefully toprotect the plant and workers safety. This adds to the cost of theoverall process. Processes which would minimize such steps, and/orrequire less capital investment, and/or have lower operating costs,would therefore be favored.

U.S. Pat. No. 3,207,770 and W. Gerhartz, et al., Ed., Ullmann'sEncyclopedia of Industrial Chemistry, 5^(th) Ed., Vol. A1, VCHVerlagsgesellschaft mbH, Weinheim, 1985, p. 545-549, describe thereaction of lower trialkylaluminum compounds (LTAC) with (usually)higher olefins. The use of higher olefins made with transition metalcontaining ethylene oligomerization catalysts is not mentioned.

U.S. Pat. Nos. 6,103,946,4,689,437, 3,644,564 and 5,382,738, which areall hereby included by reference, describe the use of various transitionmetal containing catalysts to make olefins or mixtures of olefins byoligomerizing ethylene. No mention is made of making trialkylaluminumcompounds or α-alcohols from those trialkylaluminum compounds.

B. Elvers, et al., Ed., Ullmann's Encyclopedia of Industrial Chemistry,5^(th) Ed., Vol. A28, VCH Verlagsgesellschaft mbH, Weinheim, 1996, p.505-508 and references therein, describe the overall commercialsynthesis processes for making α-alcohols, including the synthesisprocesses for making HTACs.

U.S. Pat. Nos. 2,959,607, 3,180,881,3,389,161, 3,474,122,3,494,948,4,918,254 and 5,278,330 describe a process for the productionof higher alkylaluminum compounds from (relatively) lower alkylaluminumcompounds and one or more higher olefins. The use of a transition metalcontaining ethylene oligomerization catalyst to form olefins is notdescribed. U.S. Pat. Nos. 2,959,607 and 5,278,330 also describe thesteps of oxidation of trialkylaluminums and the hydrolysis of theresulting trialkoxyaluminum compounds.

SUMMARY OF THE INVENTION

This invention concerns, a process for the manufacture of highertrialkylaluminum compounds, comprising, forming an α-olefin or mixtureof o-olefins by oligomerization of ethylene using a transition metalcontaining oligomerization catalyst system, then contacting saidα-olefin or said mixture of α-olefins with a lower trialkylaluminumcompound at a sufficient temperature, for a sufficient amount of time,to form a higher trialkylaluminum compound.

This invention also concerns a process for the manufacture ofα-alcohols, comprising:

-   -   (1) forming an α-olefin or mixture of α-olefins by        oligomerization of ethylene using a transition metal containing        oligomerization catalyst system;    -   (2) contacting said α-olefin or said mixture of α-olefins with a        lower trialkylaluminum compound at a sufficient temperature, for        a sufficient amount of time, to form a higher trialkylaluminum        compound or a mixture thereof;    -   (3) contacting said higher trialkylaluminum compound or a        mixture thereof with oxygen or other suitable oxidizing agent to        form a higher trialkoxyaluminum compound or a mixture thereof;        and    -   (4) hydrolyzing said higher trialkoxyaluminum compound or a        mixture thereof to form an α-alcohol or a mixture thereof.

DETAILS OF THE INVENTION

Herein certain terms are used, and some of them are defined below:

By a “lower trialkylaluminum compound” (LTAC) is meant a compound of theformula R³⁶ ₃Al (VI), in which each of R³⁶ contains 6 or fewer carbonatoms, preferably 2-4 carbon atoms, and each R³⁶ is independently alkyl.It is to be understood that the LTAC may contain impurities such ashydrogen bound to aluminum. Preferred LTACs are triethylaluminum andtri-i-butylaluminum.

By a “higher trialkylaluminum compound” (HTAC) is meant a compound ofthe formula R³¹ ₃Al (I), in which each of R³¹ contains 6 or more carbonatoms, preferably 8 or more carbon atoms, each R¹ is IndependentlyR³²R³³CHCH₂— wherein R³² is hydrogen or alkyl, R33 is alkyl, and eachR³¹ contains an even number of carbon atoms. Preferably R³² is hydrogenand/or R33 is n-alkyl. It is to be understood that the HTAC may containimpurities such as hydrogen bound to aluminum or alkyl groups havingless than 4 carbon atoms bound to aluminum, but at least 50 molepercent, more preferably at least 75 mole percent, and especiallypreferably at least 90 mole percent of the groups bound to aluminum areR³¹—.

By a “higher trialkoxyaluminum compound” (HTAC) is meant a compound ofthe formula (R³¹O)₃Al (III), in which each of R³¹ contains 4 or morecarbon atoms, preferably 6 or more carbon atoms, each R³¹ isindependently R³²R33CHCH₂— wherein R³² is hydrogen or alkyl, R³³ isalkyl, and each R³¹ contains an even number of carbon atoms. PreferablyR³² is hydrogen and/or R³³ is n-alkyl. It is to be understood that thehigher trialkoxyaluminum compound(s) may contain impurities such asalkoxy groups having less than 4 carbon atoms bound to aluminum, but atleast 50 mole percent, more preferably at least 75 mole percent, andespecially preferably at least 90 mole percent of the groups bound toaluminum are R³¹O—.

By an α-alcohol is meant a compound of the formula R³²R³³CHCH₂OH (II),wherein R³² is hydrogen or alkyl, R³³ is alkyl, and (II) contains aneven number of carbon atoms. Preferably R³² is hydrogen and/or R³³ isn-alkyl.

By a transition metal containing ethylene oligomerizaton catalyst ismeant a catalyst system which contains an element of Groups 3-12 (IUPACnotation) in the catalyst system, and which Is capable of oligomerizingethylene to an α-olefin. Transition metal containing “inert” supportsare not considered part of the catalyst system. By “inert” in thiscontext is meant that the support is believed to function merely as aphysical support and does not actually take part chemically in theoligomerization process.

By an “α-olefin” is meant a compound of the formula H₂C═CR³²R³³ (IV)wherein R³² is hydrogen or alkyl, R³³ is alkyl, and (IV) contains aneven number of carbon atoms. It is preferred than R³² is hydrogen and/orR³³ is n-alkyl.

Transition metal containing catalysts that oligomerize ethylene toα-olefins may be divided into two classes, those that produce a mbdureof c-olefins and those that produce (mostly) a single α-olefin. Theformer are exemplified by those catalysts found in U.S. Pat. Nos.6,103,946,2,787,626, 3,032,574, 3,207,770, 3,644,564, 3,647,915 and3,647,915, all of which are hereby included by reference. Theseoligomerizations herein may be run under conditions described in thesereferences and in other references for other such types of catalysts.Typically these catalysts produce a homologous series of α-olefins thatdiffer by two carbon atoms. The amounts of each olefin in the homologousseries typically follow a so called Schulz-Flory distribution, whichuses a factor K from the Schulz-Flory theory (see for instance B.Elvers, et al., Ed. Ullmann's Encyclopedia of Industrial Chemistry, Vol.A13, VCH Verlagsgesellschaft mbH, Weinheim, 1989, p. 243-247 and275-276, which is hereby included by reference). This is defined as:K=n(C_(n+2) olefin)/n(C_(n) olefin)wherein n(C_(n) olefin) is the number of moles of olefin containing ncarbon atoms, and n(C_(n+2) olefin) is the number of moles of olefincontaining n+2 carbon atoms, or in other words the next higher oligomerof C_(n) olefin. From this can be determined the weight (mass) fractionsof the various olefins in the resulting oligomeric reaction productmixture. The K factor is preferred to be in the range of about 0.6 toabout 0.8

A preferred type of ethylene oligomerization catalyst is described inU.S. Pat. No. 6,103,946 and World Patent Applications 01/58874,00/42123, 00/76659 and 01/19513, all of which are hereby included byreference, and similar iron tridentate catalysts which result in theformation of α-olefins. These catalysts utilize selected diimines of2,6-diacylpyridines or 2,6-pyridinedicarboxaldehydes as part of theethylene oligomerization catalyst system, particularly as ironcomplexes.

Such a preferred active ethylene oligomerization catalyst comprises aniron complex of a compound of the formula

wherein:

R¹, R² and R³ are each independently hydrogen, hydrocarbyl, substitutedhydrocarbyl or an inert functional group, provided that any two of R¹,R² and R³ vicinal to one another taken together may form a ring;

-   -   R⁴ and R⁵ are each independently hydrogen, hydrocarbyl,        substituted hydrocarbyl or an inert functional group;    -   R⁶ and R⁷ are each independently a substituted aryl having a        first ring atom bound to the imino nitrogen, provided that:    -   in R⁶, a second ring atom adjacent to said first ring atom is        bound to a halogen, a primary carbon group, a secondary carbon        group or a tertiary carbon group; and further provided that    -   in R⁶, when said second ring atom is bound to a halogen or a        primary carbon group, none, one or two of the other ring atoms        in R⁶ and R⁷ adjacent to said first ring atom are bound to a        halogen or a primary carbon group, with the remainder of the        ring atoms adjacent to said first ring atom being bound to a        hydrogen atom; or    -   in R⁶, when said second ring atom is bound to a secondary carbon        group, none, one or two of the other ring atoms in R⁶ and R⁷        adjacent to said first ring atom are bound to a halogen, a        primary carbon group or a secondary carbon group, with the        remainder of the ring atoms adjacent to said first ring atom        being bound to a hydrogen atom; or    -   in R⁶, when said second ring atom is bound to a tertiary carbon        group, none or one of the other ring atoms in R⁶ and R⁷ adjacent        to said first ring atom are bound to a tertiary carbon group,        with the remainder of the ring atoms adjacent to said first ring        atom being bound to a hydrogen atom.

A “hydrocarbyl group” is a univalent group containing only carbon andhydrogen. As examples of hydrocarbyls may be mentioned unsubstitutedalkyls, cycloalkyls and aryls. If not otherwise stated, it is preferredthat hydrocarbyl groups (and alkyl groups) herein contain 1 to about 30carbon atoms.

By “substituted hydrocarbyl” herein is meant a hydrocarbyl group thatcontains one or more substituent groups which are inert under theprocess conditions to which the compound containing these groups issubjected (e.g., an inert functional group, see below). The substituentgroups also do not substantially detrimentally interfere with theoligomerization process or operation of the oligomerization catalyst,system. If not otherwise stated, it is preferred that substitutedhydrocarbyl groups herein contain 1 to about 30 carbon atoms. Includedin the meaning of “substituted” are rings containing one or moreheteroatoms, such as nitrogen, oxygen and/or sulfur. In a substitutedhydrocarbyl, all of the hydrogens may be substituted, as intrifluoromethyl.

By “(inert) functional group” herein is meant a group, other thanhydrocarbyl or substituted hydrocarbyl, which is inert under the processconditions to which the compound containing the group is subjected. Thefunctional groups also do not substantially deleteriously interfere withany process described herein that the compound in which they are presentmay take part in. Examples of functional groups include halo (fluoro,chloro, bromo and iodo), and ether such as —OR⁵⁰ wherein R⁵⁰ ishydrocarbyl or substituted hydrocarbyl. In cases in which the functionalgroup may be near a transition metal atom, the functional group aloneshould not coordinate to the metal atom more strongly than the groups inthose compounds that are shown as coordinating to the metal atom, thatis they should not displace the desired coordinating group.

By a “primary carbon group” herein is meant a group of the formula—CH₂ - - - , wherein the free valence - - - is to any other atom, andthe bond represented by the solid line is to a ring atom of asubstituted aryl to which the primary carbon group is attached. Thus thefree valence - - - may be bonded to a hydrogen atom, a halogen atom, acarbon atom, an oxygen atom, a sulfur atom, etc. In other words, thefree valence - - - may be to hydrogen, hydrocarbyl, substitutedhydrocarbyl or a functional group. Examples of primary carbon groupsinclude —CH₃, —CH₂CH(CH₃)₂, —CH₂Cl, —CH₂C₆H₅, —OCH₃ and —CH₂OCH₃.

By a secondary carbon group is meant the group

wherein the bond represented by the solid line is to a ring atom of asubstituted aryl to which the secondary carbon group is attached, andboth free bonds represented by the dashed lines are to an atom or atomsother than hydrogen. These atoms or groups may be the same or different.In other words the free valences represented by the dashed lines may behydrocarbyl, substituted hydrocarbyl or inert functional groups.Examples of secondary carbon groups include —CH(CH₃)₂, —CHCl₂,—CH(C₆H₅)₂, cyclohexyl, —CH(CH₃)OCH₃, and —CH═CCH₃.

By a “tertiary carbon group” is meant a group of the formula

wherein the bond represented by the solid line is to a ring atom of asubstituted aryl to which the tertiary carbon group is attached, and thethree free bonds represented by the dashed lines are to an atom or atomsother than hydrogen. In other words, the bonds represented by the dashedlines are to hydrocarbyl, substituted hydrocarbyl or inert functionalgroups. Examples of tetiary carbon groups include —C(CH₃)₃, —C(C₆H₅)₃,—CC₃, —CF₃, —C(CH₃)OCH₃, —C≡CH, —C(CH₃)₂CH═CH₂, aryl and substitutedaryl such as phenyl and 1-adamantyl.

By “aryl” is meant a monovalent aromatic group in which the free valenceis to the carbon atom of an aromatic ring. An aryl may have one or morearomatic rings which may be fused, connected by single bonds or othergroups.

By “substituted aryl” is meant a monovalent aromatic group substitutedas set forth in the above definition of “substituted hydrocarbyl”.

Similar to an aryl, a substituted aryl may have one or more aromaticrings which may be fused, connected by single bonds or other groups;however, is when the substituted aryl has a heteroaromatic ring, thefree valence in the substituted aryl group can be to a heteroatom (suchas nitrogen) of the heteroaromatic ring instead of a carbon.

By a “first ring atom in R⁶ and R⁷ bound to an imino nitrogen atom” ismeant the ring atom in these groups bound to an imino nitrogen shown in(I), for example

the atoms shown in the 1-position in the rings in (II) and (III) are thefirst ring atoms bound to an imino carbon atom (other groups which maybe substituted on the aryl groups are not shown). Ring atoms adjacent tothe first ring atoms are shown, for example, in (IV) and (V), where theopen valencies to these adjacent atoms are shown by dashed lines (the2,6-positions in (IV) and the 2,6positions in (V)).

In one preferred embodiment of (I), R⁶ is

and R⁷ is

wherein:

R⁸ is a halogen, a primary carbon group, a secondary carbon group or atertiary carbon group; and

R⁹, R¹⁰, R¹¹, R¹⁴, R¹⁵, R¹⁶ and R¹⁷ are each independently hydrogen,hydrocarbyl, substituted hydrocarbyl or a functional group; providedthat:

-   -   when R⁸ is a halogen or primary carbon group none, one or two of        R¹², R¹³ and R¹⁷ are a halogen or a primary carbon group, with        the remainder of R¹², R¹³ and R¹⁷ being hydrogen; or    -   when R⁸ is a secondary carbon group, none or one of R¹², R¹³ and        R¹⁷ is a halogen, a primary carbon group or a secondary carbon        group, with the remainder of R¹², R¹³ and R¹⁷ being hydrogen; or    -   when R⁸ is a tertiary carbon group, none or one of R¹², R¹³ and        R¹⁷ is tertiary carbon group, with the remainder of R¹², R¹³ and        R¹⁷ being hydrogen;    -   and further provided that any two of R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³,        R¹⁴, R¹⁵, R¹⁶ and R¹⁷ vicinal to one another, taken together may        form a ring.

In the above formulas (VI) and (VII), R⁸ corresponds to the second ringatom adjacent to the first ring atom bound to the imino nitrogen, andR¹², R¹³ and R¹⁷ correspond to the other ring atoms adjacent to thefirst ring atom.

In compounds (I) containing (VI) and (VII), it is particularly preferredthat:

-   -   if R⁸ is a primary carbon group, R¹³ is a primary carbon group,        and R¹² and R¹⁷ are hydrogen; or    -   if R⁸ is a secondary carbon group, R¹³ is a primary carbon group        or a secondary carbon group, more preferably a secondary carbon        group, and R¹² and R¹⁷ are hydrogen; or    -   if R⁸ is a tertiary carbon group (more preferably a trihalo        tertiary carbon group such as a trihalomethyl), R¹³ is a        tertiary carbon group (more preferably a trihalotertiary group        such as a trihalomethyl), and R¹² and R¹⁷ are hydrogen; or    -   if R⁸ is a halogen, R¹³ is a halogen, and R¹² and R¹⁷ are        hydrogen.

In all specific preferred compounds (I) in which (VI) and (VII) appear,it is preferred that R¹, R² and R³ are hydrogen; and/or R⁴ and R⁵ aremethyl. It is further preferred that:

-   -   R⁹, R¹⁰, R¹¹, R¹², R¹⁴, R¹⁵, R¹⁶ and R¹⁷ are all hydrogen; R¹³        is methyl; and R⁸ is a primary carbon group, more preferably        methyl; or    -   R⁹, R¹⁰, R¹¹, R¹², R¹⁴, R¹⁵, R¹⁶ and R¹⁷ are all hydrogen; R¹³        is ethyl; and R⁸ is a primary carbon group, more preferably        ethyl; or    -   R⁹, R¹⁰, R¹¹, R¹², R¹⁴, R¹⁵, R¹⁶ and R¹⁷ are all hydrogen; R¹³        is isopropyl; and R⁸ is a primary carbon group, more preferably        isopropyl; or    -   R⁹, R¹⁰, R¹¹, R¹², R¹⁴, R¹⁵, R¹⁶ and R¹⁷ are all hydrogen; R¹³        is n-propyl; and R⁸ is a primary carbon group, more preferably        n-propyl; or    -   R⁹, R¹⁰, R¹¹, R¹², R¹⁴, R¹⁵, R¹⁶ and R¹⁷ are all hydrogen; R¹³        is chloro; and R⁸ is a halogen, more preferably chloro; or    -   R⁹, R¹⁰, R¹¹, R¹², R¹⁴, R¹⁵, R¹⁶ and R¹⁷ are all hydrogen; R¹³        is trihalomethyl, more preferably trifluoromethyl; and R⁸ is a        trihalomethyl, more preferably trifluoromethyl.

In another preferred embodiment of (I), R⁶ and R⁷ are, respectively

wherein:

R¹⁸ is a halogen, a primary carbon group, a secondary carbon group or atertiary carbon group; and

R¹⁹, R²⁰, R²³ and R²⁴ are each independently hydrogen, hydrocarbyl,substituted hydrocarbyl or a functional group;

Provided that:

-   -   when R¹⁸ is a halogen or primary carbon group none, one or two        of R²¹, R²² and R²⁵ are a halogen or a primary carbon group,        with the remainder of R²¹, R²² and R²⁵ being hydrogen;    -   when R¹⁸ is a secondary carbon group, none or one of R²¹, R² and        R²⁵ is a halogen, a primary carbon group or a secondary carbon        group, with the remainder of R²¹, R²² and R²⁵ being hydrogen;    -   when R¹⁸ is a tertiary carbon group, none or one of R²¹, R²² and        R²⁵ is a tertiary carbon group, with the remainder of R²¹, R²²        and R²⁵ being hydrogen;    -   and further provided that any two of R¹⁸, R¹⁹, R²⁰, R²¹, R²²,        R²³, R²⁴ and R²⁵ vicinal to one another, taken together may form        a ring.

In the above formulas (VII) and (IX), R¹⁸ corresponds to the second ringatom adjacent to the first ring atom bound to the imino nitrogen, andR²¹, r²² and R²⁵ correspond to the other ring atoms adjacent to thefirst ring atom.

In compounds (I) containing (VIII) and (IX), it is particularlypreferred that

-   -   if R¹⁸ is a primary carbon group, R²² is a primary carbon group,        and R²¹ and R²⁵ are hydrogen; or    -   if R¹⁸ is a secondary carbon group, R²² is a primary carbon        group or a secondary carbon group, more preferably a secondary        carbon group, and R²¹ and R²⁵ are hydrogen; or    -   if R¹⁸ is a tertiary carbon group (more preferably a trihalo        tertiary carbon group such as a trihalomethyl), R²² is a        tertiary carbon group (more preferably a trihalotertiary group        such as a trihalomethyl), and R²¹ and R⁵ are hydrogen; or    -   if R¹⁸ is a halogen, R²² is a halogen, and R²¹ and R²⁵ are        hydrogen.

In all specific preferred compounds (I) in which (VIII) and (IX) appear,it is preferred that R¹, R² and R³ are hydrogen; and/or R⁴ and R⁵ aremethyl. It is further preferred that:

-   -   R¹⁹, R²⁰, R²¹, R²³ and R²⁴ are all hydrogen; R²² is methyl; and        R¹⁸ is a primary carbon group, more preferably methyl; or    -   R¹⁹, R²⁰, R²¹, R²³ and R²⁴ are all hydrogen; R²² is ethyl; and        R¹⁸ is a primary carbon group, more preferably ethyl; or    -   R¹⁹, R²⁰, R²¹, R²³ and R²⁴ are all hydrogen; R²² is isopropyl;        and R¹⁸ is a primary carbon group, more preferably isopropyl; or    -   R¹⁹, R²⁰, R²¹, R²³ and R²⁴ are all hydrogen; R²² is n-propyl;        and R¹⁸ is a primary carbon group, more preferably n-propyl; or    -   R¹⁹, R²⁰, R²¹, R²³ and R²⁴ are all hydrogen; R²² is chloro or        bromo;    -   and R¹⁸ is a halogen, more preferably chloro or bromo.

The other type of ethylene olgimerization catalyst is typified by thatdescribed in U.S. Pat. No. 5,382,738. Typically these types of catalystsproduce (predominantly) a single olefin having a relatively low numberof carbon atoms, such as 1-hexene or 1-octene. These types of catalystsmay also be used in the present processes to oligomerize ethylene asdescribed in the references concerning these catalysts.

It is preferred that an ethylene oligomerization catalyst system thatproduces a homologous series of o-olefins be used. It is also preferredthat this catalyst system produces a product with a high molarpercentage (at least about 80 mole percent preferably at least about 90mole percent) of olefins of the formula H(CH₂CH₂)_(n)CH═CH₂ (V), whereinn is 1 or more.

The production of the HTAC from an LTAC and the α-olefin(s) can becarried out by methods known in the art, see for instance U.S. Pat. Nos.2,959,607, 3,180,881, 3,207,770, 3,389,161, 3,474,122,3,494,948,4,918,254 and 5,278,330 and W. Gerhartz, et al., Ed., Ullmann'sEncyclopedia of Industrial Chemistry, 5th Ed., Vol. A1, VCHVerlagsgesellschaft mbH, Weinheim, 1985, p. 545-549, both of which arehereby included by reference. Typical reaction temperatures are 80° C.to 150° C. for a period of about 1 hour to about 24 hours. In thisreaction it is sometimes preferred to use an LTAC whose alkyl groups arebranched, since these often are more reactive than LTACs havingunbranched alkyl groups. It is believed that the reaction of the higherolefins with an LTAC is an equilibrium reaction, for example thereaction between TEA and 1-dodecene may be written as:(C₂H₅)₃A1+3H₃C(CH₂)₉CH═CH₂3H₂C═CH₂+[H₃C(CH₂)₁₁]₃Al  1)During the reaction, which is run at, say, 100° C., the ethylene isusually volatilized, thereby driving the equilibrium to the right andresulting in (principally) tri-1-dodecylaluminum. Thus in these reactionit is preferred to run the reaction above the boiling point of thealkene which may be derived from the alkyl group of the LTAC. If olefinsare present in the olefin mixture made during the oligomerization ofethylene which also have low boiling points, they too may be distilled.

This points out an interesting variation of this process which can beused to make a combination of lower α-olefins and higher α-alcohols.Lower α-olefin are desirable for use as comonomers, while it is oftenthe α-alcohols which contain 10 or more carbon atoms which are desired.For example if one wanted to isolate octenes and lower molecular weightα-olefins from this process, one would use approximately only enoughLTAC only to react with the total amount of α-olefins having 10 or morecarbon atoms, and the reaction temperature would be controlled so thatit would be above the boiling point of 1-octene (121° C. at atmosphericpressure), so as to distill off 1-octene and lower olefins, includingthe olefin formed from the LTAC. Conveniently this can be done by usinga moderate amount of an inert solvent (see below), which preferably canbe separated from the α-alcohols which will eventually be formed bydistillation. In this instance a convenient solvent may be m-xylene(boiling point 139° C. at atmospheric pressure), much below theatmospheric boiling point of 1-decanol of 229° ° C. Thus the overallprocess may produce HTAC(s), α-alcohols, or a mixture of higherα-alcohols and (relatively) lower α-olefins.

It should be pointed out however that the reaction shown in equation 1above is an ideal one, and other side reactions may take place. Forexample one or more of the alkyl groups on the aluminum may be a2-dodecyl group instead of a 1-dodecyl group, or 1-dodecene may insertin an already formed C-Al bond of a 1-dodecyl group to give a branchedC₂₄ alkyl group attached to aluminum. These are usually relatively minorreactions when the process is run at optimum conditions (temperature forinstance). So it is possible that changing from the optimum temperatureto make the desired HTAC to also isolate some lower α-olefins may causethe HTAC(s) isolated to have a somewhat different composition (morebranching in the alkyl groups for example). These factors may be workedout by relatively simple experimentation.

Preferably the α-olefin(s) from the ethylene oligomerization reactionundergo little or no purification before being put into the process tomake the HTAC If a mixture of α-olefins are produced they are preferablynot separated. The ethylene oligomerization catalyst may be deactivatedor not (if present it may be deactivated by the usually highertemperatures of the HTAC forming process). A solvent may be used in theethylene oligomerization reaction, and preferably it does not containactive hydrogen compounds such as water, alcohols or carboxylic acids.If the solvent does not contain active hydrogen compounds it does notneed to be separated before the reactions to form the HTAC. The solventmay also be added to the process in which the HTAC is formed. Preferredsolvents in the oligomerization and/or HTAC forming reactions, if any,are nonolefinic hydrocarbons such as toluene, xylene, octane,cyclohexane, and the like. The composition of the HTAC(s) produced willdepend on the composition of the α-olefin (mixture) added to the HTACforming reaction, and as noted above the stoichiometry of the HTACforming reaction and the temperature at which it is run.

Reaction of the HTAC(s) with oxygen or other oxidizing agent to formhigher trialkoxyaluminum compounds can be carried out as known in theart, see for instance Elvers, et al., Ed., Ullmann's Encyclopedia ofIndustrial Chemistry, 5^(th) Ed., Vol. A28, VCH Verlagsgesellschaft mbH,Weinheim, 1996, p. 505-508 and references therein, and U.S. Pat. No.5,278,330 which is hereby included by reference. Likewise, thehydrolysis of the higher trialkoxyaluminum compound to form α-alcoholsmay be carried out by methods known in the literature, see for instanceElvers, et al., Ed., Ullmann's Encyclopedia of Industrial Chemistry,5^(th) Ed., Vol. A28, VCH Verlagsgesellschaft mbH, Weinheim, 1996, p.505-508 and references therein. These methods for oxidation andhydrolysis to form α-alcohols are known in the art.

The present process form making the HTAC(s) and/or α-alcohols result inless handling of pyrophoric alkylaluminum compounds at high temperaturesand/or pressure, thereby making the process safer and/or loweringoperating cost, and/or lowering investment need for the plant, whencompared to the conventional methods of manufacturing these types ofcompounds. Assuming a mixture of homologous α-olefins is used to makethe HTAC, the product mixture resulting, for example, from makingα-alcohols may be similar to that obtained with current manufacturingmethods.

The α-alcohols and α-olefins (from the reaction forming the HTAC)produced may be fully or completely purified (separated) bydistillation, as is known in the art.

1. A process for the manufacture of higher trialkylaluminum compounds,comprising, forming an α-olefin or mixture of α-olefins byoligomerization of ethylene using a transition metal containingoligomerization catalyst system, then contacting said α-olefin or saidmixture of α-olefins with a lower trialkylaluminum compound at asufficient temperature, for a sufficient amount of time, to form ahigher trialkylaluminum compound.
 2. A process for the manufacture ofα-alcohols, comprising: (1) forming an α-olefin or mixture of α-olefinsby oligomerization of ethylene using a transition metal containingoligomerization catalyst system; (2) contacting said α-olefin or saidmixture of α-olefins with a lower trialkylaluminum compound at asufficient temperature, for a sufficient amount of time, to form ahigher trialkylaluminum compound or a mixture thereof; (3) contactingsaid higher trialkylaluminum compound or a mixture thereof with oxygenor other suitable oxidizing agent to form a higher trialkoxyaluminumcompound or a mixture thereof; and (4) hydrolyzing said highertrialkoxyaluminum compound or a mixture thereof to form an α-alcohol ora mixture thereof.
 3. The process as recited in claim 1 or 2 whereinsaid mixture of olefins is used and is a homologous series of α-olefins.4. The process as recited in claim 1 or 2 wherein said homologous seriesof α-olefins is produced in an oligomerization reaction which has aSchulz-Flory constant of about 0.6 to about 0.8.
 5. The process asrecited in claim 1, 2, 3 or 4 wherein said transition metal containingoligomerization catalyst system comprises an iron complex of a diimineof a 2,6-diacylpyridine or a 2,6-pyridinedicarboxaldehyde.
 6. Theprocess as recited in claim 5 wherein said iron complex is a compound ofthe formula

wherein: R¹, R² and R³ are each independently hydrogen, hydrocarbyl,substituted hydrocarbyl or an inert functional group, provided that anytwo of R¹, R² and R³ vicinal to one another taken together may form aring; R⁴ and R⁵ are each independently hydrogen, hydrocarbyl,substituted hydrocarbyl or an inert functional group; R⁶ and R⁷ are eachindependently a substituted aryl having a first ring atom bound to theimino nitrogen, provided that: in R⁶, a second ring atom adjacent tosaid first ring atom is bound to a halogen, a primary carbon group, asecondary carbon group or a tertiary carbon group; and further providedthat in R⁶, when said second ring atom is bound to a halogen or aprimary carbon group, none, one or two of the other ring atoms in R⁶ andR⁷ adjacent to said first ring atom are bound to a halogen or a primarycarbon group, with the remainder of the ring atoms adjacent to saidfirst ring atom being bound to a hydrogen atom; or in R⁶, when saidsecond ring atom is bound to a secondary carbon group, none, one or twoof the other ring atoms in R⁶ and R⁷ adjacent to said first ring atomare bound to a halogen, a primary carbon group or a secondary carbongroup, with the remainder of the ring atoms adjacent to said first ringatom being bound to a hydrogen atom; or in R⁶, when said second ringatom is bound to a tertiary carbon group, none or one of the other ringatoms in R⁶ and R⁷ adjacent to said first ring atom are bound to atertiary carbon group, with the remainder of the ring atoms adjacent tosaid first ring atom being bound to a hydrogen atom.
 7. The process asrecited in claim 1 or 2 wherein a single α-olefin is used.